Automatic-focusing camera.



' '3. BECKER. AUTOMATIC FOCUSING CAMERA.

' Patented July 4:, 1916.

3 SHEETSSHEET 1 APPLICATIQN FILED NOV-1. 19H, 1,190,214.

1 In ventor 1. BECKER. AUTOMATIC FOCUSING CAMERA.

- APPLICATION FILED NOV. 7. I911.

Patented July 4, 1916.

3 SHEETS-MEET 2.

Inventor- 7 J. BECKER. v AUTOMATIOFOCUSING CAMERA.

APPLICATION FILED'NOV-j, I911.

' Patented July 4, 1916.

3 SHEETS-$HEET 3- EQSEPH BECKER, 0F WASHINGTQN, DISTRICT OF COLUMBIA.

'A'UTOMATIC-FOCUSING CAMERA.

Specification of Letters Patent.

Fatented July 4, 1916.

vpplication filed November '7, 1911. Serial No. 659,021.

T 0 all whom it may concern Be it known that I, Josnrrr BECKER, a citizen of the United States, residing at Washington, in the District of Columbia, have invented new and useful Improvements in Automatic-Focusing Cameras, of which the following is a specification.

The present application, identified for convenience of reference as Case U, relates to automatic copying or enlarging cameras havingthe lens, the object planeand the image plane connected by focusing gear of the radial. cam type first disclosed by Carpentier in his German Patent No. 102,004Lissued 1899.

The main object of the invention is to establish, for all classes of radial cam focusing gear, principles of construction, regulation "and adjustment, which shall be in strict conformity with the Gaussian theory of. lenses. Such principles were first disclosed, as applied to linkage focusing gear, in my prior applications, Case K, Serial No. 269,048, filed July 10, 1905, now Patent No. 1,103,342; and Case 0, Serial Nos. $2,842 and 793,262, filed October 3, 1913, now Patent N0.1,103,34-3.

' In the accompanying drawings: Figure 1 is aside elevation of a preferred form of the camera, showing the bed and mechanism sectioned on the vertical plane 1, 1-of Fig. 2; Fig. 2 is a plan; Fig. 3 is avertical section on the broken plane 3, 3 of Fig. 2; Fig.

4 is an enlarged isometric perspective of the combined slide and pivot pin which is used for the end frames' Fi 5 is a sectional ele- 7 D vation of the adjustableflens frame pivot. Fig. 6 shows my complete form of radial cam focusing gear, and Fig. 7 is a corresponding simple form; Figs. 8 and 9 are, re spectively, similar to Figs. 6, and 7, but show a moregeneralform of gear inwhich the end frame connecting points A, A are offset tomove in different parallel planes; Fig.

v10 is an inverted, plan of an enlarging camera provided with my unsymmetrical compound rectangular cam which constitutes in itself an original id-entirely novel mechanical movement; Fig. 11 is an enlarged fragmentary section of Fig. 10 on the plane determined by the axes A and D; Figs. 12 to 20, all drawn to the scale seen near Inventor, are diagrams of arrangements presenting special points of interest.

Referring to Figs. 1 to the bed of the camera comprises two parallel rails 10, 11 connected at their ends by cross heads 12, 13

and at their middle point by a cross-bar 14: which has a vertical bore 15 (Fig. 2)the axis of which is indicated by D. Cross-bar 14 is extended to form a projecting arm l6 which is provided with a uniformly wide slot 17, the median plane of which is perpendicular to the rails 10, 11 and contains the axis D of bore 15. The walls of slot 17 should be true and sufficiently well finished to provide a smooth fit for the shank 18 of a. bolt whose head 19 is adapted to bear squarely on the upper surface of arm 16. The axis (I of this bolt and axis D before mentioned are parallel and remain in the same transverse plane, but the distance CD or axle for the hub 24 of a cam disk 25.

The hub 2 is made a trifle shorter than the space between flange 21 and washer 22 to.

insure that the clamping action of the bolt shall be, confined to the sleeve washer and shall not interfere with the freedom of rotation of the hub and disln The latter is provided with two rectangularly disposed radial slots 26 and 26. Slot 26 slidingly en,- gages the squared head '27 of a pintle 28; and slot 26 similarly engages the squared head 27 of a pintle 28. The two squared heads 27, 27' are, respectively, provided with flanges 29, 29 which serve as supports for the cam disk 25 while pivot 20 of the latter is being adjusted and mounted. Pintle 28 is revolubly held in carriage 30 by a split pin 31 so that its head may turn to follow the varying inclinations of slot 26, and it is adjustably connected with the object frame 0 by a clamp bolt 32, as fully set forth in my said prior applications. Bintle 28 is said prior applications, Case K and Case 0,

and the pintles 28, are, therefore, ad-

justed .in proper relation to their respective frames by focusing on infinity, as fully explained in my said prior Cases K and 0, where substantially the same type-0f camera is shown in Figs. 19 to 22.

It may be well, however, to describe the mode of adjustment and regulation in full, as follows: Pintles 28, 2S and cam disk 25 are removed. Carriage 30 is moved up to bring its axis A into coincidencewit axis 1) and the coincidence of the axes is insured by reinserting pintle 28; then bolt .32 is loosened to free frame 0 which is then focused on an infinitely distant object to the right and bolt 32 is retightened to clamp O in fixed relation to its carriage 30 and to axis A, after which pintle 28 is Withdrawn and frame 0 is slid back with its axis A properly adjusted. larriage 30 is now moved up to bring its axis into coincidence with axis 'D and the coincidence of the axes is insured as before by reinserting pintle 28 or 28. Then bolt 32 is loosened to free frame I which is then focused on an infinitely distant object to the left and bolt 32 is retightened to clamp frame I in fixed relation to its carriage 30 and to its axis A, after which the pintle used at D is withdrawn and frame I is slid back with its axis A properly ad-. justed.

The only thing that now remains. to be done is to determine the distance CD; and

this is done automatically, after having focused one of the end frames I or O on the other, as follows: Clamp one of the end frames, say 0, at any desirable interu'iediate point of the rails 10, 11 and ha ing focused the other frame I sharply on O clamp I also, to the rails 10 and 11 in its focused relation to 0. Now, having passed the pintles 28, 28 up through their slots in disk 25, remonnt the pintles in their respective carriages and fasten them by inserting their split pins 31, 31. Cam disl; 25 is now held up by the two pintlcs 28, 28 alone, and as the carriages 30, 30 are clamped to the rails cam disk 25 may he slid around freely on the pintles and its hub 2i will. for known geometrical reasons, be constrained to inove'around in the semicircle described on A A as diameter. Having then dropped the bushing or sleeve 20 into the hub, the cam 25 is moved around until the bore of sleeve 20 is seen to register with the slot 17. 3olt 18, 15) is then inserted and the sleeve is then clamped to arm 16 by slipping on washer and firmly screwing on the nut 23. The carriages 30, 30 may now he uiu-lamped from the rails and the apparatus will be found-to.be fully regulated and adjusted ready for use without even knowing the focal length of the lens used or the extent. sign, or location of the internodal space NY as all these lens dimensions have duly and automatically been allowed for in making the several adjustments.

The structural conditions may, therefore, be summed up as follows: Noting that the distances of the pivot axis C from the principal focal planes F, F of the lens are exwhere any one of the elements m, m, m or a) considered per so may have any desirable plus or minus value, regardless of the value of f. The correctness of the principles here advanced are made self evident by the aid of my complete form of radial cam focusing gear.

The complete form, which presents the advantage of determining co-varying mechanical space elements AD, DA corresponding directly to the simultaneously c0- varying Newtonian space elements PF, F '1 of the lens, is shown in Fig. ('3. Here 50 is-a slotted plate representing the rails or bed of an enlarging camera having its lens 51 mounted in fixed position with relation to the bed 50.

The conjugate planes P, P of the lens are connected with pins A, A which slide in the slots 52, 52. Pin A is moved by the radial cam 53, pivoted at C in the focal plane F, at a distance CD equal to the focal length f from the path of A; and similarly pin A is moved by the radial cam 53 pivoted at C in the focal plane F, at a distance CD equal 7 from thepath of A. Bar 53 has an extension CE and bar 53 an equal extension CE bent around to form a right angle ACE, and the ends of these arms are connected by a link E 1 equal to CC (or FF) and fornr ing ,an articulated parallelogram CCE n which obliges AC and AC to remain perpendicularly to each other throughout all their movements, so that the right angled triangles ADC and (.TDA areand at all. times remain similar with the vertical side (D in the left triangle corresponding to the horizontal side DA in the right hand triangle, and, therefore,

whence ADDA f (2) Now as the variable PF is mechanically 133 kept equal to AD, and-the variable FP is likewise mechanically kept equal to DA we always have A simple form of slotted lever 63, 63, Fig. 7, is derived from Fig. 6 by reducing EE and CC to zero, which is done by shifting triangle CAD to the right through distance on (equal :12), and triangle C'DA to the left through the distance m (or 00) equal to FF minus m. This is the Carpentier focusing gear improved to act in strict conformity with the Gaussian theory of lenses.

If any two equal links AB, BA be added in Fig. 7, no ,variation can be produced in the distance BD by actuating the lever 63,

63; so thata third link BD may be inserted I to form a linkage gear such asdisclosed in Fig. l of my Case K. The two focusing mechanisms, therefore, cooperate, constituting a combined Becker-Carpentier focusing mechanism. p

The invariability of distance BD may be demonstrated as follows:

Let the known length of the two equal links be ABzBAza and letthe unknown distance from B to D be 2. Moreover,,let the constant product variables AD and DA be ADzu DA o so that WUICD f Then the left triangle ABD yields 2a.cos DAB AA :AD+DA u+ v so that whence equal to the square of the focal length of the lens. The two triangles ADC, CDA are, and remain, similar yielding Am W DC DA W hence, as before, in Fig. 6

ADDAzf (7) Here again, as in Fig. 6, the variable PF variable F 'P is mechanically kept equal to D'A so that we always have PFFPzADDA it and this in view of equation 7 yields PFFP f (11) which is identical with equation (3 above and with Newtons formula or equation l of my said Case K. These equations 7 to 11, being identical with equations 2 to 6, above, prove that the focuser of Fig. 8 is an exact mechanical equivalent for the focuser of Fig. 6.

From Fig. 8 is directly derived the simple form of Fig. 9, which is the type of rectangular cam shown in French patent of Stevens, No. 330,565 of March, 1903, and in Figs. 7 and 8 of British patent to Cook, No. 12,734 of 1904. i

The different simple forms of focusing is mechanically kept equal to AD, and the gear described or referred to may be distinguished by the relative positions of the 'axes of their three connecting points, with respect to the longitudinal plane drawn" through axis A parallel to the slideways in the bed of the camera. In the Becker (my) linkage (BA, BD, BA, Fig. 7) the lens point or axis D and the image points or axes A and A will all lie in the same longitudinal plane. In the Carpentier gear (63, 63, Fig. '7) the image point or axis A will be in the same longitudinal plane withA, but the lens point, or aXis C, will be offset to lie in another longitudinal plane. In the Stevens-Cook gear the three connecting points or axes A, C, A will lie in three different longitudinal planes in the order C, A, A or C, A, A. This same classification applies to the compound forms and, therefore all types shown or referred to, to wit: Becker, Carpentier, or Stevens-Cook, however much they may differas to the lateral arrangement of their three connecting points, must, it is now seen, agree exactly in the longitudinal arrangement of such points or axes, and to bring this common principle out as clearly as possible the separation of the principal foci F, F and the focal length f of the lens are made the same in Figs. 1. 2 and 6 to 10 and the conjiigate planes R, P in the same figures are set to copy double size so that FF is onehalf-'of 7, while FP is twice f. Figs. 1, 2, 6, 7, 8, 9 and 10 could, therefore, all be superposed so as to bring their six points P, F, N, N, F, P into exact.

coincidence.

The last described or Stevens-Cook form cate 93,03. The bed 10 11, 12, frames 0,

L, I, and most other features are substantially the same as in Figs. 1, 2, 3 and 5, but the carriages 100, 100 have their axes A, A offset to move in planes through the bores D, D in the middle bar 101 which has two slotted extensions 102, 103.

Points C, C are found on the circle described on A, A asdiameter, and the center of this circle which is midway between A and A must be equidistant from D and D so that the lever armsAC and AC must be unequal in all positions of the frames and levers. Arms ACand AC are also unequal for the same reason.

The two slotted levers 83 and 03, therefore, are not to be considered as mere duplicates, but as constituting in fact an entirely novel. focusing gear which is also capable of use as a mechanical movement for transmitting straight line motion from A on one line AD to A on an oifset parallel line DA.

The end frame connecting pins in this Fig. 10 are shown as mere round pins for clearness. The enlarged section Fig. 11 taken on the plane AD of Fig. 10 shows their exact construction. The spindle with squared head 97 of greater width than the spindle carries a second squared slide block 98 which turns independently on the spindle 96, and the spindle is held in place on its carriage 100 by a split pin 99.

The rules for adjusting and regulating this device are precisely the same as those given'for the form of Figs. 1 to 5. The op erator, therefore may insert his lens and proceed to adjust the device as indicated for Figs. 1 to 5, and within a few minutes he may use the camera to copy, reduce or enlarge at any desired scale and he will be able to do all this without ever knowing the focal length of the lens used or the value of any other dimension that enters into the combination.

Other fy pes.It impractical to illustrate the many different forms that can be derived by simply changing proportions, and nearly all complete forms are needlessly complicated. The following special cases, however, deserve to be mentioned. In addition to the complete forms of Figs. (3 and 8, and the simple or rectangular cam forms of 7 and 9, there exists an inter mediate more general class or type, Figs. 12 and 13 respectively derived frourthe complete forms, Figs. 6 and S, by making shifts m andm such that their sum (m+m) or (w+m) shall. difi'erfrom the distance F-F by an amount FF minus (w-l-w) which may be either positive or negative and which represents the length EE of the link that has to be used. It is only when EE equals zero that we obtain the simple forms.

A still more general form, Fig. 14 or Fig. 15 might be derived by shifting the triangles ADC, CD'A vertically as well as horizontally, and in the forms thus derived from Fig. 8 the vertical shift may be made just suliicient to bring paths. AD, DA into alinement, as in Fig. 15.

Two remarkable intermediate forms, Figs. 16 and .17 constituting in fact a distinct .type, are derived the one from Fig. (3 and into the principal plane through N, the U link E, E being equal. to .N, N.

Two remarkable simple forms l igs. 18 and 10 are similarly derived one from Fig. 6 and the other from Fig. 8, by making at equal to f and on equal to f plus NN. This reduces the distance CC and E10 to zero and brings the single remaining lens pivot G into the principal plane through N.

Fig. 20, in which 111., equal to .2", equals zero, is a diagram of the exact arrangement shown, but imperfectly di. (.zribed, by Stew ens in French latcut 330,505, of 100?. which.

*as referred to hereinbcfore in describing); Fig. 9. Figs. 12 to 20 are all drawn to the scale seen over Inventofi and they all con tain the same lens whose focalv length FN or NF equals 12 centimeters and Wii se intel-focal space FF equals 27 centimeters. in. Figs. 12 to 10 the Newtonian space AD or PF is 6 centimeters and the Newtonian space FP or DA is 24 centimeters. so that the copying factor it equals 2. in Fig. 20 the Newtonian space AD or PF is S centimeters and the Newtonian space DA or FP is 18 centimeters. so that the copying factor 12, equals 3/2. In Figs. 12, 13, 11 and '15 the shift at or .r is 3 centimeters; and the shift m or "If is S centimeters. In Figs. 10 and 17 the shifts at or a; and m or a." are all equal to or 12 centimeters. in. Figs. 15:3 and 19 the shift in or an is 12 centinie" rs, but the shift m or .11 equals the distance from N to F, or 15 centimeters. In i 20 the shift m or :1: equals FF, or 27 ccn imeters; and the shift m or .1." is fit/ j. All shifts herein shown are positive. In each of the Figs. 12 to 20 the product CD.DC being equal to or 12 by 12. must be ill. Thus in Figs. 14-. llfaud 18 it is by 1.3; in Figs. 13, 15, 17. 1?) it is 5) by 10; in Fig. 20 it is 10 by 0: whole number values being used throughout to facilitate \in'ilicatious. both by scale and computation.

No'rr: l.The kinematic efl'cct prinluccd by a rectangular radial cam such as sl'lown optical center in Figs. 2 or 7 is substantially the same as that produced by the circular cam shown in Fig. 2 of my Case T, now Patent 1,142,295 issued June 8, 1915.

NOTE 2.The EECC ered per 36, are pure linkages which disappear entirely in the simple radial cams of Figs. 2, 7, 9, 10, 1s, 19 and 20.

NOTE 3.A camera built in accordance with German Patent 102,004 of 1899 to Car pentier is of the type seen in my Fig. 7, with m, equal m, equal FN; and withpivot C set in the vertical plane containing the of the lens, at a distance CD equal FN from the slideway of pins A, A. In accordance with my invention, however, to make m equal m, we must make :0 equal av and We should have or m, equal m, equal FN plus one-half of NN, instead of m equal FN; and the pivot C should be set exactly midway between the two principal planes N, N, even when the co-called optical center is not situated midway between points N and N. 7

NOTE 4L-A camerav built in accordance with German Patent 237 ,380, issued August 7, 1911, to Kilian is substantially of the type seen in my Fig.- 7, with dimension m arbitrary as in Fig. 7. Kilian, however, makes the sum m plusm equal totwice FN instead of equal to twice FN plus the internodalspace NN, as it must be in accordance with my invention.

NOTE 5.Where the lensused happens to havean internodal space N N that is ml, the .Carpentier rule of construction, given above in Note 3, and the Kilian rule of construction, given above in Note 4, lead to results that are not in disagreement with my rule of construction as partly embodied in my equation 1; but the advantage of my rule of construction is that it is exact for all lenses or all possible values of the inter-nodal space NN, and that it is exactly and automatically satisfied by the use of the method of adjustment and regulation disclosed in my cases K and 0; so that, it practically does away with all rules of construction. That is to say, all unknown structural dimensions of a radial cam foeuser are, in view of my said cases K and O, automatically determinable by means of three simple focusing operations, without ever knowing such structural dimensions or the focal length f of the lens used and without knowing the extent, sign, or location of the inter-nodal space NN.

What I claim as my invention and desire to secure by Letters Patent is:

1. A copying or enlarging camera comprising a support for an object plane, a' support for a lens, and a support for an image receiving plane, and automatic focusing articulated parallelograms of Figs. 6, 8, and 12 to 17 considmechanism of the radial cam, type with connections to the said three supports for relatively moving two of such supports with relation to the third and having two of such connections made freely adjustable in the direction parallel to the slideway in the camera bed, to secure desired changes in the longitudinal dimensions of such connections; also a transverse adjustment to adapt the device for use with different lenses. 7 2. The combination with an automatic copying or enlarging camera having a rectangular cam focusing gear; of means for adjusting its end frame pintles with relation to their respective conjugate planes. in planes parallel to the slideway of the camera; and means for adjusting the lens pivot in a plane perpendicular to the slideway of the camera.

3. A copying or enlarging camera comprising: a support for the object; a support for the lens and a support for the image receiving surface, such three su ports being virtually: a support for the object plane P; a support for the focal planes F, F and a support for the image plane P; such camera having the supports of its left focal planes F and P connected by a radial cam pivoted to F at a distance x from F and acting on a point'A mounted in fixed relation to plane P at a distance m, equal to m, from P; said same camera also having the supports of its right hand focal planes F and P similarly connected by a radial cam pivoted to F at a distance at therefrom and acting on a point A mounted in fixed relation to P at a dis tance m equal m, from P; the distance of the cam pivots from the paths of their respectively controlled points A and A being such as to form aconstant product equal to the square of the focal length of the lens; and means to oblige the two radial cams to turn equally in perpendicular relation.

4. A copying or enlarging camera comprising: a support for the object, a support for the lens ceiving surface, such three supports being virtually: a support for the object plane P; a support for the focal planes F, F and a support for the image plane'P; such camera having the supports of its left focal planes F and P connected by a radial cam pivoted to F at a distance a; from F and acting on a point A mounted in fixed rela tion to plane P at the distance m, equal to aa, from P; said same camera also having the supports of its right hand focal planes F and 1" similarly connected by a radial cam pivoted to F at a distance a therefron'l and aciing on a point A mounted in fixed relation to I at the distance m, equal 00 from P"; the distance of the cam pivots from the paths of their respectively controlled points A and A being such as to form a constant product equal to the square of the focal length of the lens; and means to oblige the and a support for the image re 110 two radial cams to turn equally in perpendicular relation, said means consisting in an articulated parallelogram.

5. The combination with a copying or ensame pag the said [SEAL an improvement in "Automatie-Focusing Cameras,

larging camera havin a rectangular cain two subscribingWitnesses.

JOSEPH BECKER. \Vitnesses \V. E. \Vmerrr, F. E. HorKiNs.

It is hereby certified that inv Letters Patent No. 1,190,214, granted July 4, 1916,

upon the application of Joseph Becker, of Washington, District of Columbia, for

errors appear in the printed specification requiring correction as follows: Page 5, line 20, separate m from m and insert the sign of equality so that the line shall readm=rc=cc'=m'=f,;FF'= FN+-. -NN

line 26, for the compound word co-called, read so-called; and that Letters Patent should be read With these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 25th day of July, A. D., 1916.

F. W. H. CLAY,

Acting Commissioner of Patents. 

